// returning nil instead of empty slice if all spaces.
	return nil
}

// Runes interprets s as a sequence of UTF-8-encoded code points.
// It returns a slice of runes (Unicode code points) equivalent to s.
func Runes(s []byte) []rune {
	t := make([]rune, utf8.RuneCount(s))
	i := 0
	for len(s) > 0 {
		r, l := utf8.DecodeRune(s)
		t[i] = r
		i++
		s = s[l:]
	}

	}
}

func bmIndexRuneUnicode(rt *unicode.RangeTable, needle rune) func(b *testing.B, n int) {
	var rs []rune
	for _, r16 := range rt.R16 {
		for r := rune(r16.Lo); r <= rune(r16.Hi); r += rune(r16.Stride) {
			if r != needle {
				rs = append(rs, r)
			}
		}
	}
	for _, r32 := range rt.R32 {
		for r := rune(r32.Lo); r <= rune(r32.Hi); r += rune(r32.Stride) {
			if r != needle {
				rs = append(rs, r)
			}

	SelectFmtSIMDJSON
	// SelectFmtParquet - Parquet format
	SelectFmtParquet
)

// WriteCSVOpts - encapsulates options for Select CSV output
type WriteCSVOpts struct {
	FieldDelimiter rune
	Quote          rune
	QuoteEscape    rune
	AlwaysQuote    bool
}

// Record - is a type containing columns and their values.
type Record interface {
	Get(name string) (*Value, error)

	// Set a value.

// converted to int they correspond to the rune size that was read.
type readOp int8

// Don't use iota for these, as the values need to correspond with the
// names and comments, which is easier to see when being explicit.
const (
	opRead      readOp = -1 // Any other read operation.
	opInvalid   readOp = 0  // Non-read operation.
	opReadRune1 readOp = 1  // Read rune of size 1.
	opReadRune2 readOp = 2  // Read rune of size 2.

	//
	//	R1
	//	offset
	//	$offset
	// Every piece is optional, so we scan left to right and what
	// we discover tells us where we are.

	// Prefix: $.
	var prefix rune
	switch tok := p.peek(); tok {
	case '$', '*':
		prefix = rune(tok)
		p.next()
	}

	// Symbol: sym±offset(SB)
	tok := p.next()
	name := tok.String()
	if tok.ScanToken == scanner.Ident && !p.atStartOfRegister(name) {

		}
	}
}

// FieldsFuncSeq returns an iterator over subslices of s split around runs of
// Unicode code points satisfying f(c).
// The iterator yields the same subslices that would be returned by [FieldsFunc](s),
// but without constructing a new slice containing the subslices.
func FieldsFuncSeq(s []byte, f func(rune) bool) iter.Seq[[]byte] {
	return func(yield func([]byte) bool) {
		start := -1

	frame := callerFrame(4)
	if frame.PC != 0 {
		return string(strconv.AppendInt(append([]byte(frame.File), ':'), int64(frame.Line), 10))
	}

	return ""
}

func IsInvalidDBNameChar(c rune) bool {
	return !unicode.IsLetter(c) && !unicode.IsNumber(c) && c != '.' && c != '*' && c != '_' && c != '$' && c != '@'
}

// CheckTruth check string true or not
func CheckTruth(vals ...string) bool {

	b.lastRuneSize = -1
	return nil
}

// ReadRune reads a single UTF-8 encoded Unicode character and returns the
// rune and its size in bytes. If the encoded rune is invalid, it consumes one byte
// and returns unicode.ReplacementChar (U+FFFD) with a size of 1.
func (b *Reader) ReadRune() (r rune, size int, err error) {
	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil && b.w-b.r < len(b.buf) {

		}
	})
	if n > 0 {
		t.Errorf("allocations occurred while appending")
	}
}

func TestRuneIO(t *testing.T) {
	const NRune = 1000
	// Built a test slice while we write the data
	b := make([]byte, utf8.UTFMax*NRune)
	var buf Buffer
	n := 0
	for r := rune(0); r < NRune; r++ {
		size := utf8.EncodeRune(b[n:], r)
		nbytes, err := buf.WriteRune(r)
		if err != nil {
			t.Fatalf("WriteRune(%U) error: %s", r, err)

	}

	// write surrogate pair
	d.scratch.addRune(utf16.DecodeRune(r, r2))
	c = d.next()
	goto scan
}

// u4 reads four bytes following a \u escape
func (d *Decoder) u4() rune {
	// logic taken from:
	// github.com/buger/jsonparser/blob/master/escape.go#L20
	var h [4]int
	for i := range 4 {
		c := d.next()
		switch {
		case c >= '0' && c <= '9':
			h[i] = int(c - '0')